Since version 4.0.0 is the TFS plugin not supporting TFS Server 2005 (and probably TFS Server 2008) anymore. It would be nice to say the drop of support in changelog on website
https://wiki.jenkins-ci.org/display/JENKINS/Team+Foundation+Server+Plugin
Also would it be good, to have support for it in the current plugin, to get improvments.
This could be done by separate the logics into new and old TFS implementation.
This is a version of TFS that is over 10 years old. You should upgrade your TFS server and not ask an open source plugin to support such an old system. I suggest to close the issue.